Nitrocellulose-nitroglycerine explosive with ethylene oxide

ABSTRACT

Gelatinized explosive compositions comprising at least one liquid explosive nitric ester; nitrocellulose; at least one inorganic oxidizing agent; at least one carbonaceous combustible material; at least one condensation product of a lower alkylene oxide with a compound selected from the group consisting of alkyl phenols, long chain alcohols, long chain carboxylic acids, long chain amines, amides of long chain carboxylic acids and alkylolamides of long chain carboxylic acids, and optionally water.

United States Patent 72] Inventor Gwyn Harries Ripponlea, Victoria, Australia [2]] Appl. No. 850,652

[22] Filed Aug. 15, 1969 [45] Patented Nov. 2, 1971 [73] Assignee Imperial Chemical Industries of Australia and New Zealand Limited Melbourne, Victoria, Australia [32] Priority Sept. 6, 1968 [3 3] Australia [54] NITROCELLULOSE-NITROGLYCERINE EXPLOSIVE WITH ETHYLENE OXIDE 8 Claims, No Drawings [52] US. Cl 149/48, 149/50, 149/65, 149/95, 149/98 [51] Int. Cl C06b H04 [50] Field of Search 149/48, 49,

[56] References Cited UNITED STATES PATENTS 3,429,755 2/1969 Lampert 149/98 X 3,305,415 2/1967 Webb Primary Examiner-Benjamin R. Padgett Assistant Examiner-Stephen J. Lechert, Jr. Attorney-Cushman, Darby & Cushman ABSTRACT: Gelatinized explosive compositions comprising at least one liquid explosive nitric ester; nitrocellulose; at least one inorganic oxidizing agent; at least one carbonaceous combustible material; at least one condensation product ofa lower alkylene oxide with a compound selected from the group consisting of alkyl phenols, long chain alcohols, long chain carboxylic acids, long chain amines, amides of long chain carboxylic acids and alkylolamides of long chain carboxylic acids, and optionally water.

N ITROCELLULOSE-NITROGLYCERINE EXPLOSIVE WITH ETHYLENE OXIDE This invention relates to new gelatin-type dynamite compositions and, more particularly, to compositions comprising a reduced amount of explosive nitric ester.

Dynamites produced for industrial uses must be manufactured to provide a variety of specific characteristics, such as plasticity, density and explosive strength.

Because of the requirements of commercial users that for many operations the explosive composition be solid, cohesive and deformable the so-called gelatin dynamites constitute a very important type of dynamite. Gelatin compositions are produced by gelatinizing a liquid explosive nitric ester with nitrocellulose of suitable characteristics and incorporating therein a number of solid materials. The solids most frequently incorporated are oxidizing salts, combustible carbonaceous materials, stabilizers and thickeners. Nitroglycerine and ethylene glycol dinitrate and mixtures thereof are the most commonly used liquid explosive nitric esters. Nitroglycerine may also be modified by additives such as nitrobenzene or nitrotoluene. The completed blend is of a plastic consistency and is packaged in paper shells usually by an extrusion process.

A very important type of gelatin dynamites are the so-called ammonia gelatins where a portion of the liquid explosive nitric ester is replaced by ammonium nitrate. Ammonium nitrate is a high-strength explosive compound and, within limits, can be substituted for nitroglycerine without substantially altering the explosive characteristics of the composition. Such replacement is economically desirable, since the liquid nitric ester is more expensive than the ammonium nitrate. Similarly sodium nitrate may be used to prepare the so-called sodium nitrate gelatins.

Gelatin dynamites are prepared in two categories, the true gelatin, which is a relatively smooth soft solid and the semigelatin which is more crumbly. The true gelatins usually contain more liquid nitric ester than the semigelatins. For many purposes true gelatins are preferred to semigelatins for use in the field. However, hitherto there has been a definite limiting point in the amount of solids which may be introduced without loss of the plasticity essential to extrusion and field use. This point is frequently reached before the desired explosive characteristics can be obtained or before the desired degree of replacement of the liquid explosive by ammonium nitrate has been attained. Thus in practice the alternative has been hitherto, to either use true gelatins with unnecessary high contents of nitric esters or to use semigelatins with somewhat lower nitric ester content, but less desirable flow properties, water proofness and storage properties.

We have now found that lower concentrations of nitric esters may be used without detriment to explosive and flow properties if a small quantity of certain plasticity promoting agents is incorporated into the explosive mixture. This incorporation permits the preparation of satisfactory gelatin dynamites in which the liquid explosive nitric ester is present in proportions appreciably less than has heretofor been considered possible. Furthermore, for uses for which semigelatin explosives can be tolerated, we have found that the minimum amount of nitric ester required to produce the flow properties specified for semigelatin explosives, too, can be reduced below the limits hitherto accepted if a small amount of certain plasticity-promoting agents is added to the explosive mixture. Furthermore the physical storage properties are enhanced. The function of the added plasticity-promoting agent is to increase the plasticity of gelatinous explosives containing nitroglycerin or other liquid explosive nitric ester. This is particularly important in the case of gelatin dynamites containing relatively large amounts of solid inorganic nitrates for example, ammonium nitrate, sodium nitrate or both. In such explosives it is necessary to have sufficient nitroglycerin present to allow ready extrusion through an orifice into the paper shells to b e filled and to maintain plasticity for use in the field. The presence of the plasticity-promoting agents effects equivalent ease of extrusion with markedly lowered content of liquid explosive. Thus for example, with a gelatinuous explosive containing 27.5 percent w/w nitroglycerin, this content was reduced to 12.0 percent w/w by addition of a suitable plasticity-promoting agent according to this invention without undesirable effect on the extrudability, the explosive properties, either initially or after storage or the sensitivity to detonation of the explosive. Compositions satisfactory for applications requiring lower explosive power have also been extruded and these contained as little as 8 percent w/w nitroglycerin.

Accordingly we provide a gelatinized explosive composition comprising, (1) at least one liquid explosive nitric ester; (2) nitrocellulose; (3) at least one inorganic oxidizing agent; (4) at least one carbonaceous combustible material; (5) as a plasticity-promoting agent, at least one condensation product of from 2 to 12 inclusive moles, preferably from 2 to 5 inclusive moles, of ethylene oxide with a compound selected from the group consisting of alkyl phenols, long chain alcohols, long chain carboxylic acids, long chain amines, amides of long chain carboxylic acids and alkylolamides of long chain carboxylic acids; and (6) optionally water.

By long chain we mean a chain having at least eight carbon atoms and preferably more than 12 carbon atoms.

Suitable plasticity-promoting agents according to this invention are the compounds prepared by condensation of an ethylene-oxide-reactive compound selected from the group consisting of alkyl phenols, long chain alcohols, long chain carboxylic acids, long chain amines, amides of long chain carboxylic acids and alkylolamides of long chain carboxylic acids with ethylene oxide.

Amongst suitable alkyl phenols there may be mentioned octyl phenol, dioctyl phenol, nonyl phenol, dinonyl phenol, dodecyl phenol, didodecyl phenol, tributyl phenol and similarly substituted cresols, for example diisobutyl cresol and derivatives thereof. By derivatives we mean alkyl phenols bearing substituents which do not effect the phenolic and alkylic nature of the compound for example the benzyl ether or the sulfate of an octyl or nonyl phenol or alkali metal salts thereof.

Suitable long chain alcohols which may be reacted with ethylene oxide are the saturated or unsaturated longchain alcohols. Thus for example capryl alcohol, lauryl alcohol. cetyl alcohol, tridecyl alcohol, stearyl alcohol or oleyl alcohol or mixtures of these may be used.

Long chain carboxylic acids which may be reacted with ethylene oxide either by themselves or in the form of their amides or alkylolamides are the saturated or unsaturated long chain carboxylic acids. Thus, for example, caprylic acid, lauric acid, myristic acid, pentadecylic acid, palmitic acid, stearic acid, arachidic acid, oleic acid, linoleic acid, linolenic acid and ricinoleic acid or mixture or derivatives thereof may be used or their corresponding amides and alkylolamides.

Amongst suitable long chain amines which may be reacted with ethylene oxide are for example, caprylamine and stearylamine.

Useful molar ratios of ethylene oxide to ethylene-oxidereactive compound range from 2:1 to l2zl; preferred ratios range from 2:1 to 5:1. At ratios greater than 12:1 little further benefit is achieved.

Our additives are exemplified typically by the condensates set out in table I. TABLE I Number of moles of ethylene oxide per mole of ethylene oxide reactive compound Plasticity promoting TABLE I Continued Number of moles of ethylene oxide per mole of Plasticity ethylene promoting oxide agent reactive number Ethylene-oxide reactive compound compound 8 Dinonyl phenoL 8 9 Dodecyl phenol 9 10 10 Mixture of octyl and nonyl pheno1s 9 11. Diisobutyl cresol 12 12. Benzyl ether of nonyl phenol 12 13. Sulphate of nonyl phenol-sodium salt. 14 Sulphate of lauryl ether-sodium salt 3 15 Stearic acid. 16 Palmitic acid 12 17 Oleic acid 10 18 Tall oil acid 5 19 do 7 20 do. 10 21 astor oil acid. 12 22. Coconut fatty acid 10 23 Laurie acid amide 10 O 24 Stearic acid amide" l2 2 25 Coconut acid amide 2 26 Laurie acid alkylolamrda 1O Coconut acid alkylolamide. 3 -do 12 29. Coconut acid monoethanolarnide 7 30 o 10 31 Coconut acid diethanolamide 0 25 32 Tallow acid monoethanolamidc 12 33 Myristic acid diethanolamide. 12 34 Laurie acid diethanolamide. 10 35 Lauryl alcohol- 2 36 d 9 8. 39 2 30 40 3 4L 6 42 10 43 2 44 o 5 45 Sulphate of tributyl phenol-sodium salt... 3

The amount of the plasticity-promoting agent used varies with the type of plasticity-promoting agent and the composition to which it is added. Amounts from 0.1 to 5 percent w/w of the total compositions are useful; we prefer that the amount be in the range from 0.2 to 2 percent w/w ofthe total composition.

Satisfactory gelatin explosives according to our invention containing from 8.0 to 18.5 percent w/w of liquid explosive nitric ester, for example, nitroglycerine, have been prepared; below 8 percent w/w we have found that extrusion of the product becomes difficult even though the composition is still plastic. The upper limit of the concentration of liquid explosive nitric ester or a mixture or modification of liquid explosive nitric esters is merely a matter of economics. The nitrocellulose used in our compositions should be of the type conventionally used in explosives and should be present in quantity sufficient to form a thickened viscous fluid when the liquid nitric ester is partially gelatinized by solution of the nitrocellulose therein. We have found that amounts ranging from 0.4 to 1 percent w/w of the composition are satisfactory and amounts as little as 0.2 percent may be used for example when the amounts of liquid explosive nitric ester present is low, for example, 8.0 percent w/w.

We prefer that the oxygen-releasing salt be chosen from the nitrates of ammonium or the alkali metals and of these we prefer ammonium nitrate and sodium nitrate. The particle size and shape of the oxygen-releasing salt is not critical and is well known from the art ofinorganic nitrate manufacture; powders and ground prilled particles are satisfactory. The amount of oxygen-releasing salt in our compositions should be such that it constitutes more than percent w/w of the composition. Thus, for example, satisfactory compositions may be obtained when the total amount of oxygen-releasing salt, or mixtures of such salts, is in the range from to 80 percent w/w, preferably from to percent w/w, of the total composition.

Carbonaceous combustible materials should preferably be used in finely divided from and amongst suitable products, there may be mentioned asphalt, naphthalene, sugar, urea, hexamethylenetetramine, cellulosic materials such as sawdust or woodmeal, or cereal products, for example, flours, dextrins or starches. They should be present in amount in the range from 4 to 12 percent w/w, preferably from 5 to 9 percent w/w, of the total composition.

Where desirable, it is convenient to add to the compositions according to our invention, further reagents such as water, in amounts in the range from zero to 1.5 parts; conventional thickener-s, for example, guar gum, in amounts in the range from zero to two pans; conventional fillers for example, calcium carbonate, china clay, barium sulfate and ammonium phosphates in amounts in the range from zero to 10 parts; or modifiers for the liquid explosive nitric ester for example, nitrotoluene in amounts in the range from zero to nine parts, all per 100 parts by weight of the final mixture.

Accordingly we provide an explosive composition of matter comprising 1) from 8.0 to 18.5 inclusive parts of at least one liquid explosive nitric ester; (2) from 0.2 to one inclusive part of nitrocellulose; (3) from 60 to inclusive parts, preferably from 70 to 75 inclusive parts of at least one inorganic oxidizing agent selected from the group consisting of the nitrates of ammonium and the alkali metals; (4) from four to 12 inclusive parts, preferably from five to nine inclusive parts, of at least one carbonaceous combustible material; (5) as a plasticitypromoting agent from 0.2 part to two parts inclusive ofat least one condensation product of from 2 to 12 inclusive moles, preferably of from 2 to 5 inclusive moles, of ethylene oxide with a compound selected from the group consisting of alkyl phenols and derivatives thereof, alkyl cresols and derivatives thereof, long chain alcohols, long chain carboxylic acids, long chain amines, amides of long chain carboxylic acids and alkylolamides of long chain carboxylic acids and (6) optionally up to 1.5 parts of water all amounts being in parts by weight per 100 parts by weight of composition.

The compositions according to this invention are plastic masses, ranging in plasticity from soft and slightly sticky to stiff and dry which are extrudable in a deformable, solid and cohesive form. They are advantageous in that they have a lower liquid explosive content, which does not have an undesirable effect on the extrudability or on the explosive properties, and consequently there is a resultant cost saving for comparative uses. A further cost saving results in the field since our compositions have a relatively high density enabling a large weight of explosive to be packed in a given volume so minimizing the amount of drilling required for a given quantity of explosive.

Our invention is now illustrated by, but not limited to, the following examples in which parts and percentages are expressed on a weight basis.

EXAMPLES 1 TO 40 INCLUSIVE Using a conventional ribbon mixer 15 pounds of a gelatinized explosive composition was prepared by mixing the substances set out in table 11 in proportions set out in table 11. The plasticity-promoting agents used are designated as set out in table 1. The composition was then extruded into paper shells to form cartridges of the explosive composition using a cartridging machine conventionally used in the manufacture of explosives. Details of the stiffness or otherwise of the plastic extrudate and its explosive characteristics, both freshly prepared and after storage, are also set out in table 11. Examples 5 and 40 are not within our invention and are included for purposes of comparison.

NOTES ON TABLE II.

1. The sieve characteristics of the various ammonium nitrates designated were:

20% retained No.200 BSS sieve 4: passed No.18 BSS sieve 20-35% retained No.36 BSS sieve Coarse ammonium passed No.6 BSS sieve nitrate 99% retained No.36 BSS sieve 2. Cartridge count" is a measure of density after extrusion 6. A.D.C. is a contraction of the well-known Ardeer Douand the value shown is the number of cartridges each 8 inches ble Cartridge Test and is a measure of the sensitivity to long and 1 inch in diameter which weigh 50 pounds detonation of the explosive. The higher the value, the more 3. Ballistic mortar B.G. is a term indicating the power sensitive to detonation is the explosive. of the explosive compared to a blasting gelatin containing 91.2 5 V.O.D. is the velocity of detonation expressed in meters percent w/w nitroglycerine. per second when determined by the Dautriche method.

4. Water resistance hrs. is the period of time expressed in S" stiff hours, that a cartridge may be immersed in water and after this treatment be sensitive to detonation.

5. Pressure exudation is the percentage of absorbable vs: very iff material forced out of an explosive when the explosive is sub- N normal jected to a pressure of 75 lbs./sq. in. for 4 minutes. SLst. slightly sticky TABLE II Example Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Ground ammonium nitrate pri1ls(1) 73.5 74. 0 72. 9 72. 9 Ground high density ammonium nitrate prills (1) 72. 4

Fine ammonium nitrate (1) Coarse ammonium nitrate (1). Sodium nitrate Nitroglycerine. Nitrocellulose Orth0-nitrotoluene Pregelled starch.

45 Consistency of extrudate (8). Density (gm./cc.) Cartridge count (2) 164 199 Ballistic mortor percent B.G. (3) Water resistance (hours) (4) Pressure exudation percent (5) Explosive characteristics;

i ib c i 3 2 4V .m. sec.X10 (6) a 13 3% 2 4 7 10V 6 s 10 8% 10 7% 8% 5 2 2 v.0.D. m./see.X10 (7) 41 59 3e 31 22 27 sci 32 37 3a 37 42 29 63 29 30 2s 32 Storage time:

lmtXlllhIC 1 -D- .m sec. 10 3 7y 1y )6 4y 5 7 4 s 5 7% 4 7y 2 6% 4% a %D-m./sec. 10 4?; 2% 23 2% 29 42 30 30 3( 33 42 4( 26 44 26 23 -mon S.

-C.m./sec. 10 4 7 y 1 3y 3y 4 3y 6 4y 6 2% 5y 2 a 3% V2 4 -g D.m./sec. 10 54 52 2% 2% 2% 2 4o 2% 33 3% a2 31 3% 25 31 27 27 -D- .mJsec. 10 3% 6% y 3 3 1 3 2 4 3y 3 4y 2 1 5 33 2 6 -g-D-m./sec. l0 31 49 21 23 26 2% 2% 25 2% 25 32 22 21 24 25 IHOH SI -D.C.m./sec. 10 3 4 y 3 3 1 a 2 3y 3y 1y 2y 1y 1% 2% a. 95 9 .D.nn./sec.X10 27 4s 2i i3 2 3 1 26 2 g 2;, 2 2 7 3 2?) 21 2 19 mon S A.D.C.m./sec.X10 pg 3 y 1 y 1 1 y V 1% -0.D. m./sec.X10 27 40 2f 22 2% 17 20 Example Number 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 Ground ammonium nitrate prills (1 Ground high density ammonium nitrate prills (1) F'ne ammonium nitrate (1). 72. 9 73. 2 73. 2 73. 9 72. 9 73. 4 73. 9 72. 9 72. 9 72. 9 72. 9 77. 77. 0 Coarse ammonium nitrate (1 Sodium nitrate. N itroglycerine. Nitrocellulose Woodmeal Ortho-nitrotoluene Pregelled starch Guar gum Wheat flour...

Barytes Polyaerylamide Plasticity promoting agent N3. of Table I:

N N N Dens1ty(gm./cc.) 1, 1 .34 1.34 1. 43 1.48 Cartridge count (2) 175 18 176 Ballistic mortor percent water resistance (hours) (4) Pr(es)sure exudation percent A.D.C.m./sec.X (6). 10 7 83/ 65/ 9 12 9 4 4 3 3 33 5% 2* IV 10 5% 4 5 V.O.D. m. sec. 10 (7).- 33 as :32 3 7 35 44 34 2s 2s 2 9 3 9 31 3 5 2 5 4a 41 31 as 33 Storage time: 1 month:

A-D.C. m./sec. 10 6% 6 5 s 7 5 z 3 i 6% 3 1% 2V: 3 2 V.g .D.m./sec.x10 27 29 36 25 2 it? a 33 29 1s 43 26 25 32 24 mon 52 A.D.C. m./sec. 10 5% 4y 4% 5 5y 5 5 1 z 1 3% l 1 1 V.O.D. m./sec.x1o 27 2% 29 29 6 29 5? 0 29 34 2s 31 '23 4 monthsc A.D. .m./sec. (10 2% 3y 4 3 5 4 5 1 y 2y 6 V.O.D. m./sec. 10 26 2 33 5E 27 g? 5? 2 i I 16 22 22 6 months -D-C.1n./sec. 10 3 2% 3 5 l 1 1 .0.D. m./sec. 10 25 25 2 2 20 21 21 9 months 1 A.D.C.m./sec.Xi0 1y i 1 1 N t 6 V.O.D. m./sec. 10 2% 20 2 3 g1 2 4 g i 1 7 19 21 vory S. 1 Soft, S1. St.

EXAMPLE the said condensation product comprises from 2 to 5 inclusive F th f 55 moles of ethylene oxide in the molecule.

2". e purgtoseslo i s g l gg 3. A composition ofmatter according to claim 1 which compansfn i par S g. u 9 g g prises in addition an amount of water no greater than that at me ammonium m ta parts 9 mm mate an which the plastic or semiplastic property of the compound is parts of wheat flour was prepared using the apparatus and retained method of the previous examples. Attempts to extrude the composition into a deformable solid and cohesive form were exPloswe' composmorl of matter comprlsmg l from 8.0 to 18.5 inclusive parts of nitroglycerin; (2) from 0.2 to one 1 unsuccessful.

w l i inclusive part of nitrocellulose; (3) from 60 to 80 inclusive 1. An explosive composition of matter co prising (1) parts of at least one inorganic oxidizing agent selected from nitroglycerine; (2) nitrocellulose; (3) at least one inorganic the group H iStiHg f h ni rates f mm ni m n he aloxidizing agent selected from the group consisting of the Kali metals; from four l0 12 inclusive Parts of at least one nitrates of ammonium and the alkali metals; (4) at least one r nac Com i le i l and 8S 3 p i i ycarbonaceous combustible material and (5) as a plasticitypromoting agent from 0.2 part to two inclusive parts of at least promoting agent at least one condensation product of from 2 one condensation product of from 2 to 12 inclusive moles of to l2 inclusive moles of ethylene oxide with a compound ethylene oxide with a compound selected from the group conselected from the group consisting of alkyl phenols and derivasisting of alkyl phenols and derivatives thereof, alkyl cresols tives thereof, alkyl cresols and derivatives thereof, long chain and derivatives thereof, long chain alcohols, long chain caralcohols, long chain carboxylic acids, long chain amines, boxylic acids, long chain amines, amides oflong chain carboxamides of long chain carboxylic acids and alkylolamides of ylic acids and alkylolamides of long chain carboxylic acids, all long chain carboxylic acids. amounts being in parts by weight per 100 parts by weight of 2. A composition of matter according to claim 1 wherein the composition.

10 7. A composition of matter accorcfiiig to claim 4 wherein the said condensation product comprises from 2 to 5 inclusive moles of ethylene oxide in the molecule.

8. A composition of matter according to claim 4 comprising in addition water present in amount up to 1.5 parts by weight per parts by weight of the composition. 

2. A composition of matter according to claim 1 wherein the said condensation product comprises from 2 to 5 inclusive moles of ethylene oxide in the molecule.
 3. A composition of matter according to claim 1 which comprises in addition an amount of water no greater than that at which the plastic or semiplastic property of the compound is retained.
 4. An explosive composition of matter comprising (1) from 8.0 to 18.5 inclusive parts of nitroglycerin; (2) from 0.2 to one inclusive part of nitrocellulose; (3) from 60 to 80 inclusive parts of at least one inorganic oxidizing agent selected from the group consisting of the nitrates of ammonium and the alkali metals; (4) from four to 12 inclusive parts of at least one carbonaceous combustible material and (5) as a plasticity-promoting agent from 0.2 part to two inclusive parts of at least one condensation product of from 2 to 12 inclusive moles of ethylene oxide with a compound selected from the group consisting of alkyl phenols and derivatives thereof, alkyl cresols and derivatives thereof, long chain alcohols, long chain carboxylic acids, long chain amines, amides of long chain carboxylic acids and alkylolamides of long chain carboxylic acids, all amounts being in parts by weight per 100 parts by weight of the composition.
 5. A composition of matter according to claim 4 wherein there is present from 70 to 75 inclusive parts by weight of at least one inorganic oxidizing agent selected from the group consisting of the nitrates of ammonium and the alkali metals per 100 parts by weight of the composition.
 6. A composition of matter according to claim 4 wherein there is present from five to nine inclusive parts by weight of at least one carbOnaceous combustible material per 100 parts by weight of the composition.
 7. A composition of matter according to claim 4 wherein the said condensation product comprises from 2 to 5 inclusive moles of ethylene oxide in the molecule.
 8. A composition of matter according to claim 4 comprising in addition water present in amount up to 1.5 parts by weight per 100 parts by weight of the composition. 